Asaoya Yaichi

カテゴリー: Knife Care

Learn how to care for your Japanese knives with practical guides on cleaning, rust prevention, storage, and everyday maintenance to keep your knife performing at its best.

  • 刃返り Kaeri | 5 Essential Truths About the Japanese Knife Burr

    刃返り Kaeri | 5 Essential Truths About the Japanese Knife Burr


    Ishizuchi Kanamono Manufactory 

    I still remember one of my earliest experiences with a Japanese knife burr.

    I had only recently started working as a chef, and like every young cook, I was learning how to sharpen my own knives. One day, while sharpening, a tiny piece of metal suddenly came off the edge.

    I looked at it and genuinely thought part of my knife blade had broken away.

    So I went to the head chef and said something like, “Chef, part of the blade just came off. Is this okay?”

    I can still remember his face.

    He looked at me as if he was thinking, What on earth is this guy talking about?

    Looking back now, it makes me laugh.

    The blade had not fallen off at all.

    What I had seen was a Japanese knife burr coming away from the edge.

    After more than 25 years working as a chef in Japan and Australia, I have sharpened countless knives since then. But recently I realised something: although I had learned to recognise a burr through experience, I had never really stopped to investigate what it actually is.

    So, once again, I decided to look into it.

    What Is a Japanese Knife Burr?

    Asaoya Yaichi

    When sharpening a knife on a whetstone, we are removing a very small amount of steel from the blade. As the abrasive surface of the stone works against the steel, the geometry of the edge gradually changes until the sharpening reaches the very apex.

    At that point, extremely thin metal at the edge can be pushed over to the opposite side. This thin, folded-over material is what we commonly call a burr.

    In Japanese sharpening, it is often referred to as kaeri (返り), or ha-gaeri (刃返り).

    That tiny piece of metal I saw as a young chef was therefore not my knife mysteriously losing its cutting edge. It was material created during the sharpening process.

    If somebody had explained that to me at the time, I probably would not have asked my head chef whether my blade had fallen off.

    But making mistakes is often how we remember things.

    👉 INTERNAL LINK: Read “Whetstone Flattening” here

    Why Does a Japanese Knife Burr Appear?

    A Japanese knife burr can be useful because it gives us information about what is happening at the edge.

    If you sharpen one side and eventually detect a burr along the opposite side, it generally indicates that your sharpening has reached the apex in that area.

    But there is an important distinction.

    Creating a huge burr is not the goal of sharpening.

    When I was younger, I sometimes thought that if I could clearly feel a large burr, I must have sharpened the knife properly. With experience, I learned that continuing to grind away steel simply to make a larger burr is unnecessary.

    You are removing steel every time you sharpen.

    The purpose is to create a clean, properly formed cutting edge—not to remove as much metal as possible.

    👉 INTERNAL LINK: Read “How to Sharpen Japanese Knives” here

    A Bigger Japanese Knife Burr Is Not Necessarily Better

    sharpening Japanese Knife

    This is where sharpening becomes more interesting.

    A large Japanese knife burr may actually be a sign that you have continued sharpening longer than necessary. Once the abrasive has reached the apex and a burr has formed, repeatedly grinding the same side can simply produce more deformation and remove more steel.

    This connects with something I have learned through my own mistakes.

    If you keep sharpening at too high an angle, the geometry around the cutting edge can gradually become thicker. Similarly, using a whetstone that is no longer flat can affect the geometry you are trying to create.

    Sharpening is not only about making a knife feel sharp today. It is also about maintaining the blade over many years.

    👉 INTERNAL LINK: Read “Japanese Knife Bevels | Single vs Double” here

    Removing the Japanese Knife Burr Matters Too

    Forming the burr is only part of the process.

    Eventually, that weakened metal needs to be removed cleanly.

    Simply leaving a large burr attached can create the impression of an extremely sharp knife at first, but that fragile metal may fold, break away or disappear quickly during use.

    This is one reason the finishing stages of sharpening matter.

    I normally use a 1000-grit stone for my main sharpening and then move to a 6000-grit stone for finishing. The lighter work at the end is not about aggressively removing more steel. I am refining the edge and reducing what remains of the burr.

    The more knives I sharpen, the more I feel that the final light touches are just as important as the earlier grinding.

    👉 INTERNAL LINK: Read “The True Value of Japanese Knives” here

    Japanese Knife Burrs Taught Me Something About Sharpening

    Kurouchi

    There is another lesson hidden in that embarrassing story from when I first became a chef.

    Nobody starts out knowing how to sharpen.

    You can read about angles, steels, whetstones and edge geometry, but eventually you have to put a knife on a stone and learn what is happening through your hands.

    Over the years I have used carbon steels, stainless steels and modern high-performance steels, and they do not always feel exactly the same on a whetstone.

    That tactile experience is one of the things I still find fascinating about Japanese knives.

    👉 INTERNAL LINK: Read “Kireaji — What Does Sharpness Really Feel Like?” here

    The Japanese Knife Burr Is a Sign, Not the Goal

    More than 25 years after telling my head chef that “the blade came off,” I can finally give my younger self a better answer.

    Don’t worry.

    The blade didn’t fall off.

    It was just the burr.

    A Japanese knife burr is useful because it can tell us that sharpening has reached the edge, but producing the biggest possible burr does not mean producing the best possible edge.

    For me, that is the real conclusion.

    The burr is a sign during sharpening. It is not the goal of sharpening.

    And perhaps that is why I still remember that confused look on my head chef’s face all these years later.

    👉 Explore more:
    https://blog.asaoyayaichi.com.au

    👉 Visit our online store:
    https://asaoyayaichi.com.au

    Thank you for reading, and I hope to see you again in the next story.

  • Ancient Patina 古色 | 7 Powerful Truths About Japanese Knife Patina That Even Surprised Me

    Ancient Patina 古色 | 7 Powerful Truths About Japanese Knife Patina That Even Surprised Me

    Ishizuchi Kanamono Manufactory

    If you own or are thinking about buying a carbon steel Japanese knife, you’ve probably heard the term Japanese Knife Patina. Until I started selling handcrafted Japanese knives, I honestly thought any discoloration on a blade was something to avoid.

    What surprised me was discovering that many knife enthusiasts actually appreciate a beautiful patina. For some, it’s not damage at all—it’s a sign that the knife is being used, cared for, and developing its own unique character.

    In this article, I’ll explain what Japanese Knife Patina really is, how it differs from rust, and why so many experienced knife users see it as something worth embracing.

    What Is Japanese Knife Patina?

    Patina

    Japanese Knife Patina is a natural oxide layer that develops on carbon steel after repeated use. It often appears in shades of blue, grey, purple, or dark charcoal depending on the foods you cut and how you care for the knife.

    Unlike red rust, patina is generally stable and can even help slow further oxidation.

    Many professional chefs never try to remove it. Instead, they simply keep the blade clean and dry after use.

    ➡ Read more: Beginner’s Guide to Japanese Kitchen Knives

    Why Japanese Knife Patina Is Different From Rust

    One of the biggest misconceptions is that every color change means corrosion.

    Here’s the difference:

    Japanese Knife Patina

    • Blue, grey, or dark tones
    • Forms naturally during normal use
    • Can act as a protective oxide layer
    • Often appreciated by carbon steel knife users

    Rust

    • Red or orange color
    • Caused by moisture left on the blade
    • Can damage the steel if ignored
    • Should be removed as soon as possible

    Understanding this difference helps you enjoy your knife with more confidence instead of worrying every time the blade changes color.

    ➡ Read more: Why Do Japanese Knives Rust So Easily?

    Why Some Knife Enthusiasts Love Japanese Knife Patina

    This was the part that surprised me the most.

    For years I simply used carbon steel knives because they performed exceptionally well. I never thought much about the color changing over time.

    After starting Asaoya Yaichi, I learned that many collectors and professional chefs actually enjoy watching their Japanese Knife Patina develop.

    To them, every knife tells a story.

    The blade reflects years of cooking, countless ingredients, and the owner’s personal journey.

    No two patinas are exactly alike, making every knife even more unique.

    Does Everyone Want a Patina?

    Mirror Polished

    Not at all.

    Some people love the bright mirror finish of a freshly polished knife.

    Others prefer the rich character that develops through daily use.

    Neither preference is right or wrong.

    It’s simply a matter of taste.

    A mirror-polished knife highlights craftsmanship, while a beautiful Japanese Knife Patina reflects years of real-world experience.

    ➡➡ Professional Choice | Why I Still Use Carbon Steel for Sashimi After 25 Years

    How to Care for Japanese Knife Patina

    If you own a carbon steel knife, proper maintenance is still essential.

    Keep the blade clean

    Wash the knife by hand after use using mild detergent.

    Dry immediately

    Never leave water on carbon steel.

    Store properly

    Keep the knife in a dry location with good airflow.

    Don’t panic over color changes

    Blue or grey tones are often completely normal.

    The goal isn’t to prevent every change.

    The goal is to prevent red rust.

    ➡ Read more: 5 Common Mistakes That Damage Japanese Knives

    My Honest Discovery About Japanese Knife Patina

    I spent more than 25 years working as a professional chef.

    Yet one thing I didn’t truly appreciate until I started selling handcrafted Japanese knives was how differently people view Japanese Knife Patina.

    I always focused on performance.

    Many enthusiasts also appreciate the story the blade tells.

    That changed the way I look at carbon steel knives.

    A handcrafted Japanese knife isn’t just a cutting tool.

    It’s something that evolves with its owner over time.

    Perhaps that’s one of the reasons handmade Japanese knives continue to fascinate so many people around the world.

    ➡ Read more: Handmade Japanese Knives | 7 Fascinating Reasons No Two Are Ever Exactly the Same

    Final Thoughts

    Whether you prefer a mirror finish or a naturally developed Japanese Knife Patina, both represent different ways of appreciating handcrafted Japanese knives.

    One celebrates perfection.

    The other celebrates experience.

    Whichever you prefer, the most important thing is to enjoy using your knife and taking proper care of it.

    👉 Explore more:
    https://blog.asaoyayaichi.com.au

    👉 Visit our online store:
    https://asaoyayaichi.com.au

    Thank you for reading, and I hope to see you again in the next story.

  • Why Do Japanese Knives Rust So Easily? (And Why That’s Not a Bad Thing)

    Why Do Japanese Knives Rust So Easily? (And Why That’s Not a Bad Thing)

    Ishizuchi Kanamono Manufactory

    One of the most common questions I hear is:

    “Why does my Japanese knife rust so easily?”

    It’s a fair question. After all, many people expect an expensive knife to stay shiny and rust-free forever.

    But with traditional Japanese knives, rust isn’t a sign of poor quality. In many cases, it’s actually a sign of what makes the knife special.

    Why Carbon Steel Rusts

    Asaoya Yaichi

    Many handcrafted Japanese knives are made from high-carbon steel, such as Aogami (Blue Steel) or Shirogami (White Steel).

    These steels are loved by professional chefs because they offer exceptional sharpness, excellent edge retention, and are easier to sharpen than many stainless steels.

    The trade-off is that carbon steel reacts more easily with moisture and acidic foods, so it can develop rust if left wet.

    My Own Experience

    I learned this the hard way.

    Even after rinsing my knife with water, I once left it sitting for a while after cutting citrus fruit.

    When I came back, small spots of rust had already started to appear.

    It wasn’t because the knife was poorly made.

    It was because the acid from the citrus remained on the blade long enough to react with the carbon steel.

    Since then, I’ve made it a habit to wash my knives, dry them immediately, and never leave them sitting wet.

    Rust Doesn’t Mean a Bad Knife


    180mm Kiritsuke Aogami #2 Kurouchi Walnut Octagonal Handle

    Many of Japan’s finest kitchen knives are made from carbon steel.

    Professional chefs continue to choose them because they value cutting performance over convenience.

    A little extra care is a small price to pay for a knife that delivers incredible sharpness and can last for decades.

    How to Prevent Rust

    Knife Care

    Keeping a carbon steel knife in great condition is simple.

    • Wash it soon after use.
    • Dry it thoroughly with a clean towel.
    • Never leave it soaking in water.
    • Be extra careful after cutting acidic foods such as lemons, limes, or tomatoes.
    Tsubaki Oil
    • If storing the knife for an extended period, apply a thin coat of camellia oil (tsubaki oil), which has traditionally been used in Japan to protect carbon steel from rust. If you don’t have camellia oil, a small amount of food-grade cooking oil can also be used as a temporary alternative.

    What If Rust Already Appears?

    Don’t panic if you notice rust on your knife.

    In many cases, light surface rust can be removed before it causes any serious damage.

    Depending on the severity of the rust, you may be able to remove it by:

    • Sharpening the blade on a whetstone.
    • Gently polishing the affected area with fine-grit sandpaper.
    • Using a rust eraser designed for knives and tools, such as products commonly known in Japan as Sabitoru.

    The most important thing is to deal with rust as soon as you notice it. The longer rust remains on the blade, the more difficult it can become to remove.

    Prevention Is Better Than Restoration


    240mm Thick Deba Aogami #2 Kurouchi Walnut Handle

    One of the best ways to keep a carbon steel knife in excellent condition is to prevent rust from forming in the first place.

    Once rust starts to develop, the affected areas can become more susceptible to rusting again if they are not properly cleaned and protected.

    That’s why it’s best to care for your knife from the day you buy it. Keeping the blade clean and dry from the beginning is the easiest way to maintain both its appearance and its cutting performance for years to come.

    As with most knife care, prevention is always easier than restoration.

    Final Thoughts


    180mm Santoku VG10N 33 Layer Damascus Green Marble Handle Rainbow Spacer Blue

    Carbon steel knives aren’t difficult to own—they’re simply different.

    Once you understand how to care for them, you’ll see why so many professional chefs continue to choose carbon steel over stainless steel.

    However, if you’re not confident that you’ll be able to give a carbon steel knife the care it needs, there’s nothing wrong with choosing a stainless steel knife instead.

    A knife that suits your lifestyle is always a better choice than one that causes unnecessary stress.

    At Asaoya Yaichi, we proudly offer authentic handcrafted Tosa knives made by skilled Japanese craftspeople, including both carbon steel and stainless steel options.

    If you’re looking for an authentic Japanese knife, we’d be happy to help you find the one that’s right for you.

    Explore our collection at:

    https://www.asaoyayaichi.com.au

    From Tosa, Japan, to your kitchen.

  • Why Flattening Your Whetstone Matters More Than You Think

    Why Flattening Your Whetstone Matters More Than You Think

    When I first became a chef, I had no idea that whetstones needed to be flattened.

    For nearly two years, I sharpened my knives on the same stone without ever checking if it was still flat.

    The knives became sharp enough for work, so I assumed everything was fine.

    Then one day, while visiting Japan, I took one of my knives back to the shop where I had bought it.

    The craftsman looked at it and simply said,

    “That’s no good!”

    It was a little embarrassing, but it became one of the most valuable lessons I ever learned about sharpening.

    What Is Whetstone Flattening?

    Whetston

    Every time you sharpen a knife, your whetstone slowly wears down.

    Because the centre is used the most, it gradually becomes lower than the edges.

    Even if you can’t easily see it, that slight hollow can affect how your knife is sharpened.

    Flattening simply restores the whetstone back to a perfectly flat surface.

    Why Is It Important?


    165mm Kiritsuke Thick Deba Aogami #2 Kurouchi Walnut Octagonal Handle

    Japanese knives are designed with precise edge geometry.

    If your whetstone isn’t flat:

    • The edge won’t contact the stone evenly.
    • It’s much harder to keep a consistent sharpening angle.
    • The bevel can become uneven.
    • Sharpening becomes less predictable.

    Sometimes people think they’ve forgotten how to sharpen.

    In reality, the problem may simply be the condition of the whetstone.

    How to Flatten Your Whetstone

    I simply use a standard flattening stone designed for whetstones.

    Before I begin, I draw a light grid across the whetstone using a permanent marker.

    There’s no need to colour the whole surface—just a simple grid is enough.

    Wet both stones and rub them together using even pressure.

    And the house was a rental.

    As the surface becomes flat, the marker lines gradually disappear.

    If some lines remain, those areas are still lower than the rest of the stone.

    Once all the lines disappear evenly, rinse the stone thoroughly and it’s ready to use again.

    It only takes a few minutes, but it makes a huge difference to your sharpening.

    A Funny Story From One of My Former Chefs

    Why Flattening Your Whetstone Matters

    One of the chefs I used to work with had a very different way of flattening his whetstones.

    Instead of using a flattening stone, he rubbed them directly on the smooth concrete in his backyard.

    To be fair…

    It actually worked surprisingly well.

    A smooth concrete surface allows you to apply good pressure and removes the high spots quite effectively.

    The only problem was that it left grey sharpening marks and stains all over the concrete.

    Even now, I sometimes wonder if everything went smoothly when he moved out!

    So yes, it can work in an emergency.

    But unless you’re prepared to explain mysterious grey stains to your wife, partner, or landlord, I probably wouldn’t recommend it.

    If you’re renting, it’s definitely best to avoid using your driveway or patio.

    5 Common Mistakes That Damage Japanese Knives

    If you really prefer this method, a better option would be to buy a smooth concrete paver or a flat tile and use that instead.

    Just make sure it’s genuinely flat. If the surface isn’t flat, your whetstone won’t be either. Also, some tiles are so smooth that they don’t remove material very effectively.

    For consistent results, a proper flattening stone is still the easiest and most reliable solution.

    What I Learned


    210mm Gyuto VG10 Polished Hammered 67 Layer Damascus Green Handleす

    Back then, I thought that as long as my knife became sharp, I was doing everything correctly.

    Now I know that good sharpening doesn’t begin with the knife.

    It begins with a flat whetstone.

    Sometimes the smallest maintenance habits make the biggest difference.

    Looking After Your Japanese Knife

    A quality Japanese knife doesn’t require complicated maintenance.

    Keep it clean, dry it properly, sharpen it when needed, and remember to maintain your whetstone as well.

    With proper care, a handcrafted Tosa knife can last for many years.

    At Asaoya Yaichi, we’re proud to offer authentic handcrafted Tosa knives made by skilled craftsmen in Kochi, Japan.

    Explore our collection at:

    www.asaoyayaichi.com.au

    From Tosa, Japan, to your kitchen.

  • Why Flattening Your Whetstone Matters

    Why Flattening Your Whetstone Matters

    Knife Care

    When a knife does not become as sharp as expected, many people assume the problem is their technique or the knife itself.

    But sometimes, the real problem is the whetstone.

    As a whetstone is used, its surface gradually wears down. Because we often sharpen in the same area, the centre can become hollow. Flattening restores the stone to an even surface so the blade can make consistent contact while sharpening.

    What Happens When the Stone Is Not Flat?

    Sharpening on a hollow whetstone can make it difficult to maintain a consistent angle.

    The blade may still become sharp enough to cut, but the bevel can become uneven. It may also be difficult to raise an even burr along the entire edge, and over time the shape of the blade may be affected.

    This is something I learned through experience.

    A Lesson From My Early Years as a Chef

    When I first became a chef, I used a whetstone that was kept at the restaurant.

    It had not been flattened and was already noticeably hollow. At the time, I did not understand why that mattered.

    My knives became sharp enough to use, so I continued sharpening on that same stone for around two years.

    Later, while visiting Japan, I took one of my knives back to the shop where I had bought it in Kappabashi and asked them to sharpen it.

    The person looked at the knife and said:

    “This is no good.”

    He laughed dismissively, but did not explain what was wrong, why it had happened, or how I could correct it.

    I will not name the shop. However, I never bought another knife from them.

    I accept that my sharpening was not good. But beginners cannot improve when they are only criticised and given no explanation.

    How Often Should You Flatten a Whetstone?

    There is no single rule.

    It depends on how often you sharpen, the hardness of the stone and the amount of pressure you use.

    Some people flatten their stone before every sharpening session. Others check it after sharpening several knives.

    The important thing is to inspect the surface regularly and flatten it before the hollow becomes too deep.

    What That Experience Taught Me


    180mm Santoku VG10 Polished Hammered 67 Layer Damascus Green Handle

    Today, I find myself selling knives.

    At the moment, Asaoya Yaichi does not offer a professional sharpening service, and I do not pretend to be a sharpening specialist.

    However, I do want to treat customers differently from the way I was treated.

    People should not be made to feel embarrassed because they are beginners or because they have made a mistake. I made plenty of mistakes myself, including sharpening on an unflattened whetstone for two years.

    When possible, I want to explain:

    • What has gone wrong
    • Why it matters
    • What can be done next

    Selling a knife should not be the end of the relationship.

    Good information and simple maintenance can help a well-made knife remain part of someone’s kitchen for many years.

    Looking for a Japanese Knife Made to Last?

    Asaoya Yaichi

    At Asaoya Yaichi, we offer handcrafted Tosa knives made by skilled Japanese craftspeople.

    Whether you are buying your first Japanese knife or adding to your collection, proper sharpening and whetstone maintenance will help it perform at its best.

    Explore our collection of authentic handcrafted Tosa knives.

    From Tosa, Japan, to your kitchen.

    https://www.asaoyayaichi.com.au

  • 5 Common Mistakes That Damage Japanese Knives

    5 Common Mistakes That Damage Japanese Knives

    Lessons I’ve Learned After More Than 25 Years as a Chef


    180mm Santoku Aogami #2 Green Micarta Handle with Turquoise Spacer

    Japanese knives are often described as delicate or difficult to maintain.

    From my experience, that’s not true.

    After more than 25 years working as a chef in both Japan and Australia, I’ve found that most damage doesn’t happen while you’re cooking—it happens afterwards.

    Rust, cracked handles, warped blades, and unnecessary repairs are often the result of a few simple habits that are easy to avoid.

    Here are the five most common mistakes I’ve seen over the years, including a few I’ve learned from my own experience.

    1. Leaving the Knife Wet After Use

    If I had to choose the biggest cause of rust, this would be it.

    After cooking, it’s easy to leave a knife on the cutting board or beside the sink while cleaning up.

    Unfortunately, even a short period of moisture combined with food residue can start the rusting process.

    Carbon steel is especially vulnerable, but stainless steel isn’t completely immune either.

    A simple routine makes all the difference:

    • Wash the knife soon after use.
    • Dry it thoroughly.
    • Store it somewhere dry.

    Those extra 30 seconds can add years to your knife’s life.

    2. Only Rinsing the Knife After Cutting Citrus Fruits

    Most people know that citrus fruits such as lemons and limes can affect a knife because of their acidity.

    What I’ve personally experienced, however, is that simply rinsing the blade with water isn’t always enough.

    I have rusted a knife myself after cutting citrus and only washing it with water.

    Acid and juice can remain on the blade, especially near the edge, the heel, or where the blade meets the handle.

    After cutting citrus, I always recommend:

    • Wash the knife properly with mild dishwashing liquid.
    • Rinse with clean water.
    • Dry it immediately and completely.

    It’s a small habit that can prevent unnecessary rust.

    3. Ignoring Small Rust Spots

    Small rust spots are much easier to deal with than deep rust.

    Once rust starts penetrating into the steel, removing it becomes much more difficult and time-consuming.

    I’ve learned that preventing rust is always easier than restoring a damaged blade.

    If you notice rust beginning to form, don’t leave it for another day.

    Deal with it early.

    Your knife will thank you for it.

    4. Washing the Knife with Very Hot Water

    Many people know not to use a dishwasher.

    What isn’t discussed as often is washing a knife by hand with very hot water.

    In my experience, repeatedly exposing a knife to very hot water can shorten its lifespan.

    The blade can be placed under unnecessary stress from repeated temperature changes, while the wooden handle suffers even more.

    Over time, excessive heat can cause the handle to:

    • Dry out
    • Expand and contract repeatedly
    • Develop small cracks
    • Split
    • Loosen around the tang
    • Eventually begin to rot from moisture entering through damaged areas

    Once a wooden handle starts cracking, water and food residue can work their way inside, making it more difficult to keep clean and shortening the life of the handle.

    Warm water is all you need.

    Wash the knife quickly, dry both the blade and the handle immediately, and avoid soaking it.

    5. Putting the Knife in the Dishwasher

    This is probably the most well-known mistake, but it’s still worth mentioning.

    Dishwashers expose knives to:

    • High temperatures
    • Strong detergents
    • Long periods of moisture
    • Contact with other utensils

    These conditions can damage both the blade and the wooden handle.

    Even if no damage is visible after one cycle, repeated dishwasher use can significantly shorten the knife’s lifespan.

    A handcrafted Japanese knife deserves to be washed by hand.

    Fortunately, that only takes a minute.

    Japanese Knives Aren’t Difficult to Maintain

    One of the biggest misconceptions is that Japanese knives require complicated maintenance.

    In reality, they don’t.

    Simply remember to:

    • Wash the knife soon after use.
    • Don’t leave it wet.
    • Properly wash it after cutting citrus fruits.
    • Remove rust before it becomes serious.
    • Avoid very hot water.
    • Never use a dishwasher.
    • Dry both the blade and the wooden handle thoroughly.

    None of these steps are difficult.

    They simply become good habits.

    Final Thoughts

    After more than 25 years in professional kitchens, I’ve learned that good knife care isn’t about doing something special.

    It’s about avoiding a few simple mistakes.

    The difference between a knife that lasts five years and one that lasts several decades often comes down to daily habits.

    I still own a knife that has been in my family for over 40 years.

    The reason it’s still in use today isn’t because it received special treatment.

    It’s because someone took the time to wash it, dry it, and care for it properly after every use.

    If you do the same, a quality Japanese knife can reward you with many years of reliable service.

    Looking for a Knife Built to Last?

    Asaoya Yaichi

    The handcrafted Tosa knives available from Asaoya Yaichi are made by skilled Japanese craftspeople and designed for real daily use.

    With proper care, they can remain reliable kitchen tools for many years.

    Explore our collection of authentic handcrafted Tosa knives and find a knife that suits your cooking style.

    From Tosa, Japan, to your kitchen.

    Ready to find the right knife for your kitchen?

    Explore the Asaoya Yaichi collection of authentic handcrafted Tosa knives:

    https://www.asaoyayaichi.com.au

  • How Often Should You Really Sharpen a Japanese Knife?

    How Often Should You Really Sharpen a Japanese Knife?

    A Chef’s Honest Perspective


    I use an electric sharpener at home.

    One of the most common questions I hear is:

    “How often should I sharpen my Japanese knife?”

    The answer might surprise you.

    After more than 25 years working as a chef in both Japan and Australia, I’ve learned that there isn’t a single correct answer.

    Every chef develops their own routine based on the knives they use, the ingredients they prepare, and the standards they set for themselves.

    My Routine May Surprise You


    240mm Thick Deba Aogami #2 Kurouchi Walnut Handle

    To be completely honest, I don’t fully sharpen my knives every day.

    In my own routine, I usually do a proper sharpening on a 1000-grit whetstone about once a week.

    During service, if I feel the edge beginning to lose its bite, I’ll often touch it up lightly on a 6000-grit finishing stone to keep the knife performing consistently until my next full sharpening.

    That approach has worked well for me throughout many years in professional kitchens.

    Every Chef Is Different


    A Chef’s Daily-Cared-For Knife

    At the same time, I’ve worked alongside chefs whose approach is completely different.

    Some sharpen their knives every single day.

    Some go even further, polishing their blades with mirror-polishing compounds until they achieve an incredibly refined finish.

    When you use one of those knives, the difference can be astonishing.

    I’ve borrowed colleagues’ knives before and genuinely thought,

    “Wow… this thing is unbelievably sharp.”

    Those moments remind me that there is always something new to learn.

    I’m Still Learning Too

    People sometimes assume that because I’ve been a chef for over 25 years, I must be a master sharpener.

    The truth is, I don’t see myself that way.

    There are many chefs whose sharpening skills are better than mine, and I’m perfectly happy to admit that.

    Sharpening is a craft in itself.

    Like cooking, it’s something you can continue improving for a lifetime.

    I believe being honest about that is more valuable than pretending to know everything.

    The Goal Isn’t Perfection

    Otori,Scallop,Scampi Sashimi

    For professional chefs, the goal isn’t always creating the sharpest knife imaginable.

    The real goal is having a knife that performs reliably, safely, and consistently throughout service.

    For home cooks, the standard is even simpler.

    You don’t need to sharpen your knife every week just because a professional chef does.

    If your knife still cuts cleanly and feels comfortable to use, it’s probably doing exactly what you need.

    Listen to Your Knife

    Instead of following someone else’s schedule, learn to pay attention to your knife.

    Is it crushing tomatoes instead of slicing them?

    Does it slip instead of biting into ingredients?

    Does it require more pressure than it used to?

    Those are much better indicators than the calendar.

    Every knife tells you when it’s time.

    You simply have to learn how to listen.

    A Final Thought


    When I’m not in the kitchen, I’m probably squid fishing.

    One lesson I’ve learned throughout my career is that there is no single “correct” way to care for a Japanese knife.

    Different chefs have different routines.

    Different kitchens have different demands.

    What matters most is finding a routine that keeps your knife performing well and encourages you to enjoy using it.

    A well-maintained Japanese knife isn’t about chasing perfection.

    It’s about building a relationship with a tool that can serve you for many years.

    Looking for a Japanese knife worth caring for?

    At Asaoya Yaichi, we carefully select authentic handcrafted Tosa knives made by skilled Japanese blacksmiths.

    Whether you’re buying your first Japanese knife or adding to an existing collection, our goal is to help you find a knife you’ll enjoy using—and maintaining—for years to come.

    Explore our collection here:

    https://www.asaoyayaichi.com.au

  • How to Care for Your Japanese Knife | Keep It Sharp for Years

    How to Care for Your Japanese Knife | Keep It Sharp for Years

    Buying a quality Japanese knife is just the beginning.

    With proper care, a handcrafted knife can provide exceptional performance for many years—often decades. Unfortunately, many knives lose their edge prematurely, not because they’re poor quality, but because they’re cared for incorrectly.

    After more than 25 years working as a chef in Japan and Australia, I’ve seen many excellent knives damaged by simple mistakes that are easy to avoid.

    1. Wash Your Knife by Hand

    Always wash your knife by hand using warm water and a mild detergent.

    Never leave it soaking in the sink, and avoid putting it in the dishwasher. The high heat, harsh detergents, and contact with other utensils can damage both the blade and the handle.

    After washing, dry the knife immediately with a soft towel.

    2. Use the Right Cutting Board

    A quality knife deserves a quality cutting surface.

    Wooden and soft rubber cutting boards are ideal because they are gentle on the edge.

    Glass, ceramic, marble, granite, or very hard plastic boards will dull even the best knife much faster.

    3. Don’t Twist or Pry

    Japanese knives are designed for precise slicing.

    Avoid twisting the blade while cutting or using it to pry frozen food, bones, or hard shells. Doing so can chip or damage the edge.

    Instead, let the knife do the work with smooth, controlled cuts.

    4. Store Your Knife Properly

    Never throw your knife loosely into a drawer.

    Use a knife block, magnetic knife rack, or a blade guard to protect the edge and improve safety.

    Proper storage also helps prevent accidental damage to the blade.

    5. Sharpen Before It Becomes Completely Dull

    Many people wait until their knife struggles to cut before sharpening it.

    In reality, regular maintenance keeps the knife performing at its best and usually removes less steel over time.

    A whetstone remains the best method for maintaining a traditional Japanese knife.

    Carbon Steel vs Stainless Steel

    Different steels require different levels of care.

    Carbon steel can develop a beautiful natural patina with use, but it should always be dried immediately after washing to prevent rust.

    Stainless steel is more resistant to corrosion and generally easier to maintain, making it a great choice for many home cooks.

    Neither is “better”—they simply suit different users and cooking styles.

    A Good Knife Is Meant to Last

    One of the greatest pleasures of owning a handcrafted Japanese knife is watching it improve with age.

    As the handle develops character and the blade is maintained over the years, the knife becomes uniquely yours.

    With proper care, a handcrafted knife isn’t simply a kitchen tool—it’s an investment that can accompany you through thousands of meals.

    At Asaoya Yaichi, we carefully select authentic handcrafted knives from Tosa, Japan, believing that quality craftsmanship deserves proper care and appreciation.

    If you’re looking for a genuine Japanese knife that will last for many years, we invite you to explore our collection.

    Browse our collection:
    https://www.asaoyayaichi.com.au

    Read more knife guides:
    https://blog.asaoyayaichi.com.au